It is known to clean a fabric article, such as clothing, by laundering it with a laundry detergent, and then to soften or condition it by applying a fabric softening or conditioning composition. The fabric softening or conditioning composition (hereinafter “fabric enhancer”) typically contains a cationic softening or conditioning agent, which may interact with the anionic surfactants typically contained in the laundry detergent compositions to form flocculation or “scum” that will adversely affect both the cleaning and softening/conditioning performances of both products. Therefore, the conventional fabric enhancer is added in the rinse cycle of the laundering process, after the wash cycle has already been completed and most of the laundry detergent has already been drained off with the washing liquor.
The trend for washing is to use an automatic laundry washing machine wherein a laundry detergent and a fabric enhancer are dispensed from the washing machine via two separate compartments, thereby ensuring the automated release of the laundry detergent at the beginning of the washing cycle and of the fabric enhancer during the subsequent rinse cycle, usually near the end of the rinse cycle, or where multiple rinses are selected, during the final rinse process. This way, direct contact between the laundry detergent and the fabric enhancer is minimized during the laundering process.
However, such separate dispensing compartments still cannot completely prevent undesired contact between the laundry detergent and the fabric enhancer. For example, they may have dispensing outlets that are placed too close to each other, or even open into a common liquid pipeline. Residues of the laundry detergent and the fabric enhancer may be left near such dispensing outlets and/or inside the common liquid pipeline, thereby coming into contact with each other. Significant gelling has been observed between the laundry detergent in its undiluted form (i.e., before it is diluted by water) and the fabric enhancer in its undiluted form. Particularly, the undiluted laundry detergent and the undiluted fabric enhancer, when mixed together in an approximately 1:1 ratio, may form a highly viscous, gel-like composition. Such gel-like composition may either block the dispensing outlets or pipelines in the automatic laundry washing machines, or leave visible residue on fabrics due to its high viscosity.
Therefore, there is a continuing need for an easy and cost-effective method to mitigate or eliminate the above-mentioned gelling issue.